25 August 2010
Transparency refers to the extent you can see through an object on the Stage, and correlates to the level of opaqueness applied to an object's alpha properties.
To set the transparency of an object in Adobe Flash Professional, you must first convert it to a symbol. Each instance of a symbol has its own color effects, including transparency. Use the Property inspector to set transparency options (Color Effect: Alpha) for symbol instances. Settings applied in the Property inspector also affect bitmap graphics placed inside symbols.
When you change the level of transparency for an instance in a specific frame, Flash makes the change as soon as it displays that frame. To make gradual color changes, apply a motion tween. When tweening transparency, set different transparency settings in the starting and ending keyframes of an instance and then tween the span of frames between the two keyframes to make the instance's transparency shift over time.
Note: If you apply a color or transparency effect to a movie clip symbol that has multiple frames, Flash applies the effect to every frame in the movie clip symbol.
In the animation above, the alpha property of the blue circles tweens from 100% to 0%, while the alpha property of the orange triangles tweens from 0% to 100%.
In the Property inspector, choose either the Alpha or Advanced options from the Style menu in the Color Effect section to set the transparency values. Choose Alpha if you want to adjust only the transparency settings; Advanced allows you to set transparency and RGB color values simultaneously.
You can also change the transparency of an instance using the ActionScript alpha property. When you programmatically change the alpha value, you specify a value between 0–1 (rather than 0–100%). To learn more about controlling transparency by using ActionScript to set the values the alpha object, see the section titled alpha property in the ActionScript 3 Reference.

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License